1. Field of the Invention
The present invention relates to an enriched natural anti-oxidative blend in the form of an amorphous powder, and, more particularly to a process for obtaining such blend by an extraction process from Emblica officinalis fruit, which has advantageous antioxidant and free radical captodative properties, and cosmetic, pharmaceutical and nutritional use compositions thereof, particularly for protection of the skin against the sun and its damaging ultraviolet radiation.
2. Description of the Prior Art
As it is well known, L-ascorbic acid (vitamin C) is a naturally-occurring compound found in many fruits and vegetables. L-ascorbic acid functions in many biological processes such as collagen synthesis, anti-oxidation, intestinal absorption of iron and metabolism of some amino acids. An essential function of L-ascorbic acid in these processes is to act as a cofactor for the hydroxylation of proline and lysine residues in collagen, a major protein component of the body. L-ascorbic acid also increases the transcription rate of procollagen genes and stabilizes procollagen mRNA. Its well-known ability to cure scurvy, for example, may be also due to the stimulation of collagen synthesis in connective tissues.
While ascorbic acid possesses many indispensable biological properties, it has several disadvantages. For example, it is susceptible to air oxidation and sensitive to heat, and is unstable in aqueous solution, even under neutral pH and at room temperature. To solve these problems, the art has stabilized ascorbic acid by complexation with cyclodextrin, zeolites or liposomes. Another approach consists of stabilizing ascorbic acid by derivatization of its ene-diol function at the 2-position, for example, as L-ascorbic acid 2-phosphate or L-ascorbic acid 2-sulfate. The ascorbic acid 2-phosphate derivative does show some biological activity, however, ascorbic acid 2-sulfate is no longer an effective biological agent.
The provision of a stable ester at the 2-position of ascorbic acid also has been proposed. Monoalkyl esters having 1 to 18 carbon atoms, fluoroalkyl esters having 2 to 7 carbons and from 4 to 15 atoms of fluorine, and substituted benzoyl or cinnamate esters have been prepared for this purpose.
It is important to note that ascorbic acid can react with metal ions, such as iron and copper to yield active oxygen species and may act as a dangerous prooxidant [(B. Halliwell, Free Radical Research, 25, 439-54 (1996)].